Bloodwork can be checked to look at amylase and lipase
levels, if they are elevated it is a sign of pancreatic
inflamation, yet some people who have had the disease for a while no longer show elevated a&p levels. Other tests include fecal fat analysis, trypsinogen tests, ultrasounds, ct-scans, EUS and ERCP's. Often one test is not enough and it takes a combination of varied tests to reach a clear diagnosis.
I hope this answers some of your questions.